This invention relates to a rail-mounted mobile system such as a mobile storage system, and more particularly to a rail splice arrangement for such a system.
A rail-mounted mobile system, such as a mobile storage system, includes one or more movable members supported on a series of spaced apart parallel rails. In a mobile storage application, the movable members are typically in the form of carriages having wheels that are supported on the spaced apart rails. A series of storage units, such as shelves or cabinets, are mounted to each carriage.
Prior art rail arrangements for mobile storage systems of this type typically include a series of rail sections that are aligned in end-to-end relationship to form a desired rail length. Splices or joints are formed between the ends of adjacent rail sections. Each rail section typically includes a base member and a support member defining a support surface with which the carriage wheels are engaged. The base member provides the means by which the support member is mounted to a support surface such as a floor, and includes provisions for leveling the support surface and for facilitating mounting of the rail section to the floor.
In a prior art rail construction, the base member of each rail section includes a lower wall, and the end of the support member is located in alignment with the end of the lower wall of the base member. Typically, the rail sections are positioned on a subfloor so as to be in alignment with each other, and the elevation of the rail sections is adjusted so as to level the support surfaces defined by the aligned support members. Grout is then injected into the space between the subfloor and the base members, to maintain the rail sections at the desired elevation. An upper floor is installed over the subfloor to raise the elevation of the finished floor to the level of the top of the base members of the rail sections. In this prior art construction, in which the ends of the support members overlie the ends of the base members, the movement of the loaded storage units over the splices or joints between the adjacent rail sections can cause the ends of the rail sections to apply a vertical pounding force on the grout below the base members as the carriage moves from one rail section to another. Over time, this can significantly deteriorate the condition of the grout and cause the support surfaces of the adjacent rail sections to be moved out of vertical alignment with each other. This vertical misalignment of adjacent support surfaces adversely affects operation of the system by creating a bump or drop, which the wheels of the carriage must negotiate in order to pass from one rail section to another.
It is an object of the present invention to provide a rail arrangement for a rail-mounted mobile system, such as a mobile storage system, which prevents vertical misalignment between the support surfaces of adjacent support members forming a part of adjacent rail sections. It is a further object of the invention to provide such a rail arrangement having a generally similar construction and operation as in the prior art, while maintaining the support surfaces of adjacent rail section support members in vertical alignment with each other. It is a further object of the invention to provide such a rail arrangement in which the support members of adjacent rail sections are maintained in horizontal alignment with each other. Yet another object of the invention is to provide such a rail arrangement which is configured so as to prevent grout located below the rail sections from being directly exposed to vertical forces resulting from movement of the carriage from one rail section to another.
In accordance with the present invention, a rail arrangement for a mobile storage system includes at least first and second rail sections that are adapted to be aligned with each other for supporting a movable member, such as a carriage associated with a mobile storage system. Each rail section includes a base member and a support member. The support members define upwardly facing support surfaces that are adapted to be engaged by wheels or the like associated with the carriage. The base members of the rail sections define facing ends that are adapted to be placed adjacent each other to form a joint therebetween. The support members of the rail sections also define facing ends that are adapted to be placed adjacent each other to form a joint therebetween. The joint between the support members of the rail sections is offset from the joint between the base members of the rail sections. In this manner, the joint between the support members of the rail sections overlies one of the base members, so that any vertical forces resulting from movement of the carriage wheels from one support member to another are applied to the base member rather than to the open area between the ends of the base members as in the prior art, to isolate the grout below the base members from the adverse effects of such forces.
The base member of each rail section is preferably formed to include a lower wall and a pair of upwardly extending side walls between which the support member of each rail section is located. The joint between the ends of the support members is located over the lower wall of the base member of one of the rail sections.
The joint between the ends of the support members further includes engagement structure for maintaining the support members in horizontal alignment with each other. The engagement structure may be in the form of a projection that extends from the end of one of the support members, and which is received within a groove formed in the end of the adjacent support member. The projection and the groove are configured so as to prevent lateral movement between the support members, to ensure that the support members remain in horizontal alignment.
The invention contemplates a mobile storage system having a rail arrangement, as well as a rail construction and a method of engaging a pair of rail sections, substantially in accordance with the foregoing summary.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.